Your shield must be at zero to achieve this trophy. Even having just 1% of your shield will not work. When you are airborne, you can tilt or to perform somersaults. Performing a double somersault and landing it perfectly will unlock the trophy. A perfect landing is defined as having all four wheels of your vehicle touch the ground at the same time.
There are numerous jumps and drops where you can obtain this but if you want it quick, create a game on the London map and pick a light class (Assassin, Scout or Engineer are the best for it.) When the match starts, look for the large launch pad in either the red or blue base. These look like many blue rings ascending from the floor. Drive into the center and press to jump and you’ll be lifted into the air (the higher the rings go, the better the elevation). When this happens, tilt the stick to begin somersaulting and once you’ve completed two full circles, straighten out before you touch the ground. If done correctly, your shields will be full and the trophy will unlock. If not, you can try again from the center of the ring until you are successful.